$fontSize:12px;
@mixin zoomImg($width:100%, $percentage) {  /*$percentage  百分比*/
  width:$width;
  >div{
    width:100%;
    padding-top:$percentage;
    position:relative;
    >img{
      position:absolute;
      top:0;
      left: 0;
      right: 0;
      bottom:0;
      margin: auto;
      max-height: 100%;
      max-width: 100%;
    }
  }
}

@mixin firstLine($fontSize:$fontSize,$fontWeight:normal){
  &::first-line{
    font-weight: $fontWeight;
    font-size: $fontSize;
  }
}

@mixin boxShadow {
  box-shadow:0 0 10px 1px rgba(0,0,0,0.2);
}

@function toPrec($width,$height){//根据宽和高得到百分比
  @return $height/$width*100%;
}


@mixin center(){               /*水平垂直居中*/
  position: absolute;
  left: 50%;
  top:50%;
  transform: translate(-50%,-50%);
}